A procedure for preconcentration of Mn（Ⅱ）, Fe（Ⅱ）, Co（H）, Cu（Ⅱ）, Cd（Ⅱ）, Zn（Ⅱ）, Pb（Ⅱ） and Ni（Ⅱ） based on retention of their complexes with 8-hydroxyquinoline （HQ） on Amberlite XAD-2000 resin in ...A procedure for preconcentration of Mn（Ⅱ）, Fe（Ⅱ）, Co（H）, Cu（Ⅱ）, Cd（Ⅱ）, Zn（Ⅱ）, Pb（Ⅱ） and Ni（Ⅱ） based on retention of their complexes with 8-hydroxyquinoline （HQ） on Amberlite XAD-2000 resin in a column was proposed for the analysis of environmental samples by flame AAS. Various parameters such as pH, eluent type, volume, concentration, flow rate and volume of sample solution, and matrix interference effect on the retention of the metal ions were investigated. The optimum pHs for the retention of metal complexes in question were about 6 except for Mn^2＋ for whose value is 8. The loading capacity of the adsorbent for these metals and their recoveries from the resin under the optimum conditions were in the range 6.82-9.26 mg·g^-1 and 95%-101%, respectively. The enrichment factor was calculated as 100 and the limit of detection was in the range 0.3-2.2 μg·L^-1 （n=20, blank＋ 3s）. The proposed enrichment method was applied to tap water, stream water and vegetable samples. The validation of the procedure was carried out by analysis of certified reference material and standard addition. The analytes were determined with a relative standard deviation lower than 6% in all samples.展开更多
Objective: To compare the protective effects of removingcirculatory TNF by specific immunoadsorption and by nonspeciflc Amberlite XAD-7 adsorption on experimental endotoxin shock. Methods: New Zealand white rabbits re...Objective: To compare the protective effects of removingcirculatory TNF by specific immunoadsorption and by nonspeciflc Amberlite XAD-7 adsorption on experimental endotoxin shock. Methods: New Zealand white rabbits receiving a lethal dose of endotoxin underwent hemoperfusion through immunoadsorbent or Amberlite BAD-7. Plasma TNF levels. efficiency of the adsorbents and the survival rate were observed. Results: After 2 h of hemopcrfusion through immunoadsorhent or Amberlite XAD-7. plasma TNF levels were significantly lower than those in the control group(P<0.01). and the best result was shown by immunoadsorption (P<0. 01). The 12 h and 18 h survival rates were 70% and 30% in the immunoadsorption group, and 30% and 5% in the Amberlite XAD-7 group respectively (P<0. 05). Conclusion: Compared with the nonspecific Amberlite XAD-7 adsorption,the specific imrnunoadsorption might be a more effective method of removing circulatory TNF and improve the survival rate in endotoxin shock.展开更多
Synthetic resin, Amberlite XAD-4 was linked covalently with the third generation supramolecule, octa-O-methoxy resorcin [4] arene through -N=N-group to form chelating resin, which has been characterized and effectivel...Synthetic resin, Amberlite XAD-4 was linked covalently with the third generation supramolecule, octa-O-methoxy resorcin [4] arene through -N=N-group to form chelating resin, which has been characterized and effectively used for the separation and preconcentration of metal ions such as Ni(II), Cu(II), Zn(II) and Cd(II). Critical parameters such as pH, flow rate, sorption capacity, breakthrough studies, distribution coefficient, preconcentration factor, concentration of eluting agents responsible for quantitative extraction of metal ions were optimized. The synthesized resin showed good binding affinity towards Ni(II), Cu(II), Zn(II) and Cd(II) under selective pH conditions. Good breakthrough capacity and fast exchange kinetics of the resin lead to effective separation of metal ions from their binary and ternary mixture by column method on the basis of pH and eluting agents. The resin could be reused for about 8 -10 cycles. The proposed method having the analytical data with the relative standard deviation (RSD) 2% and with recoveries of analytes higher than 98%, reflects upon the reproducibility and reliability of the method which has been successfully applied in the separation and determination of Ni(II), Cu(II), Zn(II) and Cd(II) ions in synthetic, natural and ground water samples.展开更多
A membrane process for metal recovery from aqueous solutions was studied. Metal ions diffused from the feed compartment to the stripping compartment through an hybrid Donnan dialysis which consists to combine two ion ...A membrane process for metal recovery from aqueous solutions was studied. Metal ions diffused from the feed compartment to the stripping compartment through an hybrid Donnan dialysis which consists to combine two ion exchange membranes with solvent impregnated resin (SIR). The aim of this work is to study the recovery of Pb(II), Ag(I) and Cu(II) from nitrate solutions by using SIR combined with classical Donnan dialysis. The resin has been prepared by impregnating the Amberlite XAD-4 using three different extractants namely: di-2-ethyl hexyl phosphine acide (D2EHPA), tris-octyl phosphine oxide (TOPO) and Diphenylthiourea (DPT). Experiments were performed as a function of nature of the extractant impregnated on the XAD-4 resin as well as the concentration in the resin phase, the stripping pH, the concentration ratio of metal ions in the feed compartment and the nature of the counter ions in strip compartment. The results show that the D2EHPA is the better extractant for the metal ions used in this work, and it’s shown a good selectivity for the separation between ions.展开更多
文摘A procedure for preconcentration of Mn（Ⅱ）, Fe（Ⅱ）, Co（H）, Cu（Ⅱ）, Cd（Ⅱ）, Zn（Ⅱ）, Pb（Ⅱ） and Ni（Ⅱ） based on retention of their complexes with 8-hydroxyquinoline （HQ） on Amberlite XAD-2000 resin in a column was proposed for the analysis of environmental samples by flame AAS. Various parameters such as pH, eluent type, volume, concentration, flow rate and volume of sample solution, and matrix interference effect on the retention of the metal ions were investigated. The optimum pHs for the retention of metal complexes in question were about 6 except for Mn^2＋ for whose value is 8. The loading capacity of the adsorbent for these metals and their recoveries from the resin under the optimum conditions were in the range 6.82-9.26 mg·g^-1 and 95%-101%, respectively. The enrichment factor was calculated as 100 and the limit of detection was in the range 0.3-2.2 μg·L^-1 （n=20, blank＋ 3s）. The proposed enrichment method was applied to tap water, stream water and vegetable samples. The validation of the procedure was carried out by analysis of certified reference material and standard addition. The analytes were determined with a relative standard deviation lower than 6% in all samples.
文摘Objective: To compare the protective effects of removingcirculatory TNF by specific immunoadsorption and by nonspeciflc Amberlite XAD-7 adsorption on experimental endotoxin shock. Methods: New Zealand white rabbits receiving a lethal dose of endotoxin underwent hemoperfusion through immunoadsorbent or Amberlite BAD-7. Plasma TNF levels. efficiency of the adsorbents and the survival rate were observed. Results: After 2 h of hemopcrfusion through immunoadsorhent or Amberlite XAD-7. plasma TNF levels were significantly lower than those in the control group(P<0.01). and the best result was shown by immunoadsorption (P<0. 01). The 12 h and 18 h survival rates were 70% and 30% in the immunoadsorption group, and 30% and 5% in the Amberlite XAD-7 group respectively (P<0. 05). Conclusion: Compared with the nonspecific Amberlite XAD-7 adsorption,the specific imrnunoadsorption might be a more effective method of removing circulatory TNF and improve the survival rate in endotoxin shock.
文摘Synthetic resin, Amberlite XAD-4 was linked covalently with the third generation supramolecule, octa-O-methoxy resorcin [4] arene through -N=N-group to form chelating resin, which has been characterized and effectively used for the separation and preconcentration of metal ions such as Ni(II), Cu(II), Zn(II) and Cd(II). Critical parameters such as pH, flow rate, sorption capacity, breakthrough studies, distribution coefficient, preconcentration factor, concentration of eluting agents responsible for quantitative extraction of metal ions were optimized. The synthesized resin showed good binding affinity towards Ni(II), Cu(II), Zn(II) and Cd(II) under selective pH conditions. Good breakthrough capacity and fast exchange kinetics of the resin lead to effective separation of metal ions from their binary and ternary mixture by column method on the basis of pH and eluting agents. The resin could be reused for about 8 -10 cycles. The proposed method having the analytical data with the relative standard deviation (RSD) 2% and with recoveries of analytes higher than 98%, reflects upon the reproducibility and reliability of the method which has been successfully applied in the separation and determination of Ni(II), Cu(II), Zn(II) and Cd(II) ions in synthetic, natural and ground water samples.
文摘A membrane process for metal recovery from aqueous solutions was studied. Metal ions diffused from the feed compartment to the stripping compartment through an hybrid Donnan dialysis which consists to combine two ion exchange membranes with solvent impregnated resin (SIR). The aim of this work is to study the recovery of Pb(II), Ag(I) and Cu(II) from nitrate solutions by using SIR combined with classical Donnan dialysis. The resin has been prepared by impregnating the Amberlite XAD-4 using three different extractants namely: di-2-ethyl hexyl phosphine acide (D2EHPA), tris-octyl phosphine oxide (TOPO) and Diphenylthiourea (DPT). Experiments were performed as a function of nature of the extractant impregnated on the XAD-4 resin as well as the concentration in the resin phase, the stripping pH, the concentration ratio of metal ions in the feed compartment and the nature of the counter ions in strip compartment. The results show that the D2EHPA is the better extractant for the metal ions used in this work, and it’s shown a good selectivity for the separation between ions.
